1. Field of the Invention
The present invention relates to vents for air circulation, particularly from outdoors to indoors such as home soffit vents, barn vents, building vents and the like. More specifically, it relates to such vents that close in response to elevated heat with the objective being to have a closing response to the heat of fire to reduce or eliminate vent based updrafting.
2. Information Disclosure Statement
The following is representative of mechanical systems with ventilator structures:
U.S. Pat. No. 2,718,187 issued to Frisby describes a ventilator comprising a frame member which defines a central opening through which air may pass, a screen member, of substantially the same dimensions as those of the frame, attached to the frame and covering the central opening, a cover plate of substantially the same dimensions as that of the central opening pivotally mounted on the frame over the central opening. The cover plate is spring biased to selectively assume either one of two stable equilibrium positions with respect to the central opening, the frame defining first and second bores extending therethrough and located respectively on opposite sides of the pivotal mounting point whereby actuating forces may be selectively brought to bear through the bores onto the cover plate to cause the cover plate to assume selectively said stable equilibrium positions.
U.S. Pat. No. 2,755,728 issued to Frisby describes a ventilator which includes a rectangular frame having a rectangular central opening. There are ledges on one side of the frame along opposed edges thereof, a screen, means for fastening the screen to the ledges in parallel relation to the frame, the frame defining holes therethrough perpendicular to the plane of the screen whereby the frame may be mounted on a base with the screen held between the frame and the base. The ledges are narrower than the frame whereby there are spaces between the screen and the frame along the inner walls of the ledges, a spring mounted on one of the ledges and extending into the space adjacent that ledge toward the opposing ledge, and a rectangular closure plate having one dimension slightly greater than the distance from the spring to the opposing ledge and having its other dimension slightly less than the complementary dimension of the rectangular opening and being held by said ledges under the action of the spring.
U.S. Pat. No. 3,899,156 issued to McCabe describes a fire damper for use in small openings which includes a single blade articulated about a hinge within a frame. The blade is movable between an open and closed position. In the open position a fusible link and strap retain the blade. When the link is released a negator extension-type spring mounted on the frame forces the blade to close the opening through the frame. A blade lock mounted on the blade engages the frame to retain the blade in the closed position.
U.S. Pat. No. 4,562,853 issued to Techirkey et al describes a plurality of valve structures which are incorporated in a drill pipe string for drilling a well into the earth utilizing air as the drilling fluid. A valve is located in the drill pipe string just above the drilling bit, and an additional valve or valves are located in upwardly spaced relation within the drill collar string. Each of the valves has a valve member held in a position allowing the flow of air through the valve by a fusible support, and when the support melts, the valve member will shift to a position closing the valve. The valve just above the bit is combined with a float valve to prevent the upward flow of fluid into the drill string, while the valve or valves spaced upwardly in the drill collar string are full opening valves which allow the running of instruments through the drill string to selected locations above the bit. The additionally upwardly spaced valve or valves include a flap held in a position to one side of the bore through the valve body by a fusible retainer. When the fusible retainer melts, releasing the flap, the flap seats on the sleeve to shut off the flow of fluid through the valve and through the drill pipe string and cause an increase in pressure of air above the closed valve.
U.S. Pat. No. 4,667,581 issued to Hovland describes a ventilator for attachment to a building soffit which is opened or closed automatically in response to a critical wind velocity. The ventilator includes a damper hingeably attached thereto which is acted upon by a wind of a predetermined velocity to cover the ventilator opening into the building and thereby prevents the introduction of wind-blown snow, rain or other particulate matter into the building.
United Kingdom Patent No. 1,416,763 describes a thermally actuable fire protection valve which is for a ceiling outlet in an air-conditioning installation, the valve includes an air box which has a laterally directable air inlet opening and a fire resistant flap adapted to close the outlet opening, one end of the flap being hinged to the side of the box opposite the inlet opening and the flap being held inclined to the air outlet opening, the open position within the box, by a thermally releasable arresting device.
Japanese Patent No. 53-64,942 describes a fire prevention damper to be opened and closed which is provided within the body, which is isolated from the external air, and it is mechanically held in an open state via temperature fuse. The temperature fuse of this fire prevention damper is constituted by a shaft, a cylinder and a heat reception member, with the shaft and cylinder secured to each other by soldering.
United Kingdom Patent No. 2,141,928A issued to Tanner describes a ventilator device which includes a casing having one or more openings for passage of ventilation air therethrough, a shutter within the casing and normally held retracted from the one or more openings, first means for urging the shutter to a position to close the one or more openings, and second means actuation of which releases the shutter to cause it to be moved by the first means to close the one or more openings.
Notwithstanding the prior art, the present invention is neither taught nor rendered obvious thereby.